Hubble Space Telescope in 'safe mode' after gyroscope failure

By Mike Wall

October 08, 2018, 4:40:13 PM EDT

Hubble, which has been observing the heavens since 1990, went into a protective safe mode on Friday (Oct. 5) after another one of its orientation-maintaining gyroscopes failed.

"On Friday, the Hubble Space Telescope went into safe mode due to a failed gyro — used to keep the telescope precisely pointed for long periods. Mission experts are taking steps to return Hubble to great science. More updates will follow," mission team members wrote Monday (Oct. 8) via Hubble's Twitter account.

NASA's Hubble Space Telescope, which launched to Earth orbit in April 1990, is in safe mode after experiencing a gyroscope failure. Credit: NASA

The news began to trickle out on Twitter as a rumor over the weekend. Rachel Osten, Hubble's deputy mission head at the Space Telescope Science Institute (STScI) in Baltimore, confirmed that rumor with tweets of her own.

"It’s true. Very stressful weekend. Right now HST is in safe mode while we figure out what to do. Another gyro failed. First step is try to bring back the last gyro, which had been off, and is being problematic," Osten tweeted Sunday (Oct. 7).

Hubble has six gyroscopes, all of which were replaced by spacewalking astronauts during a servicing mission in May 2009. The telescope needs three working gyroscopes to "ensure optimal efficiency," mission team members have written, and the failure brings that number down to two (if the "problematic" one that had been off can't be brought back online).